VAN-DER-WAALS VIBRATIONS OF NO-METHANE COMPLEXES IN THE A(2)SIGMA(+) STATE

The (1+1) resonance enhanced two-photon ionization spectra of NO-metha ne van der Waals (vdW) complexes associated with the A(2) Sigma(+)-X(2 )II transition of the NO moiety were measured using a time-of-flight m ass spectrometer. The band origin of NO-CH4 vdW complex is determined as 44103.7 cm(-1). In the low transition energy region of 44080-44180 cm(-1), the origin band and two vdW bands were observed and each of th e bands consisted of four peaks due to the internal rotation of methan e. An analysis of the internal rotation gave the V-3 anisotropic param eters of 114-153 and 35 cm(-1) in the A(2) Sigma(+) and X(2)II states, respectively.